Ultraviolet flashlight and energizing unit therefor



C. WEEKS ULTRAVIOLET FLASHLIGHT AND ENERGIZING UNIT THEREFOR Filed Dec. 9, 1'950 2 SHEETS-SHEET l Oct. 7, 1952 C. WEEKS ULTRAVIQLET FLASHLIGHT AND ENERGIZING UNIT THEREFOR 2 SHEETS-SHEET 2 Filed Dec. 9, 1950 llttliflitlllllllllil www mm A w l w N 9 E lriivll viii I FATAL k Patented Oct. 7, 1952 UNITED STATES PATENT t me I I ULTRAVIOLET FLASHLIGHT AND ENERGIZING UNIT' THEREFOR. v

Charles Weeks, Menlo Park, Calif.,' assignor to I Menlo Research Laboratory, Menlo Park, Calif.

a copartnership Application December 9, 1950, Serial Nb. 200,010} f My invention relates to an improved ultraviolet flashlight and energizing unit therefor,

characterized by simplicity and inexpensiveness of construction, reliable and efficient operation,

smallsize-and light weight, andvfreedom from undesirable vibration.

In prospecting, examination of art works and documents for changes, and for other purposes, ultra-violet lightgives data that cannot otherwise be obtained. However,- the ultra-violet light sources heretofore available have required a source of power current and in addition are bulky and heavy, thus being unsuitable for use in'remote or inaccessible locations where the requisite energizingv power cannot conveniently be obtained.

In accordance with the present'invention an ultra-violetflashlight is providedwhich isen- .tirely self-energized and operates in a simple and convenient manner in many respects similar to the operation of a conventional flashlight and has the small size and lightweight characteristics similarto a flashlight. Briefly, the unit of the I present invention comprises an elongated conducting tube in which a transformer unit, a vibrartorunit, and conventional flashlight batteries are received. 1 A switch accessible from outside the casing or tube operates, when depressed, to establishan electrical energizing circuit fr'om the batteries to-the vibrator and hence the primary coil of the transformer. n low pressure 1 mercury vapor lamp producing light of the characteristic mercury ultra-violet wavelengths is connected across the secondary of the transformer and is energized whenthe switch is actuated. The

mercury vaporlampconsistsof an elongated tube with a'spiral light emitting portion parallelto andadjacent a visiblelight filter and a pair of parallel electrode carrying leg portions extending .baclgwardly from the spiral portion. The lamp is sustained by resilientsupport elements received by the housing and in engagement with the leg portionsof the lamp. The ultra-violet light output is concentrated in the viewingdirection by ahighly' efflcient reflector mounted in the housing forthegtube. I

-' It is therefore a general object of; the present inventionto provide an improved ultra-violet flashlight and an energizingu-nit therefor.

Another object of thepresent invention is to provide :anfimproved ultra-violet flashlight of light weight and small size suitable'forhand h portable use. I

Anotherrobject' of the' present invention is I to v 6 Claims; (Cl. 240-10.6)

- provide an improved ultra-violet flashlight unit cie ntly energizing. the lamp from wherein the light emitting area of the lamp is efilciently utilized. "1

A further object of the present inventoin isto provide an improved self con'tained energizing unit for a mercury vapor lamp capable of effiself-contained flashlight type batteries." j

'A further object of'the present invention is to provide an improvedjself-contained energizing unit, a mercury vapor lamp characterized by simplicity, ease of handling, ready replacement of parts, and reliability.'

' 'The novel featuresjwhichI believe to be characteristic of my invention are set forth with particularity in theappended claims. My invention itself, however, both as to its'organization, nature of operation, as well other objectsand' advantages thereof, will best be understood by'reference to the following description taken in Con unction with the accompanying drawing, in which:

Figure 1 is a side elevational view with parts in axial cross-section of a complete ultra-violet flashlight constructed in accordance with the principles'of the present inventionj C Figu're2 is an enlarged axial "cross-sectional view'with parts in elevationofa fragmentary portion of the energizing part of the unit of Figure 1;

Figure 3 is an enlarged axial cross-sectional view of the lamp and adjacent housing portions therefor of the unit of Figure 1;

Figure ljis aIfragmentary cross-sectional view through axis llyFigure 2 showing the swivel slip ring'coupling between'the lamp and theener- .gizing unit;

I lii'e'ure 5 is a view'in perspective of the lamp it- 'self;' t

. Figure '6 Ba viewiri perspective'of tn vibrator unit;and, r I

Figure '7 is ajschematic circuit diagram of the jd evice. I f

fReferring nowto Figure 1, there is shownlgenerally atE the battery containing energizing unit for the ultra-violet flashlight and at L the lamp unit therefor; 'Thesetwo units arejoined by a swiveljoint, indicated generally at S, which'permits rotation of the lamp unit relative tothe energizing unit while maintaining the necessary electrical connection therebetweeni I r The lamp unit consists of :a' darkchamber housing "In which is-of cylindrical cup-shaped conformation, and has, a detachable end cap I2 :which seals the same an d supports thesample being inspected. Alternatively, the cap [2 may be ;-omitted-and the open end of the housing ll] pressed against the object being examined. The closed top end of the housing ID is apertured to receive the eye piece l4 having an eye-receiving cap Ma through which the interior of the housing [8 may be viewed. The lamp housing 16 also opens into the housing ID to illuminate the contents thereof with ultra-violet light as hereafter described.

When the ultra-violet flashlight is used, the.

energizing unit E through the swivel connection S energizes the lamp in housing Iii-to illuminate the interior of housing In for viewing through the eye piece 14. Preferably theeyepiece Mincludes magnifying elements to aid inspection.

The mechanism contained within the lamp .the ultra-violet filter "26- is held. The lamp ll8 is supported immediately inback! of filter 26by the. joint action of the reflectorjdisk28, the cushioning insert 30 which snugly receives the legs I'Baand' we of thelamp l,8,and thecushioning insert32 which receives the ends ofv legs 'l8aa'nd 18b. ifl'hecu'shioning or shock mount insertsii3fl and .32 .may be vof any suitable cushioning material, such as, forv examplespongerubber.

Reflector .disk 28 iis-of circular shape totbe .received in vthe sleeve 20 andhas an elongated slottoreceiverthellegs'l8aror 'l8b of the tube l8.

.Preferablythis reflector is of aluminum with .a

reflective surface, known in the trade ,as an ..Alzak" reflector. .Thismaterial has the. property "of. reflecting 90. per .centofthe ultra-vibletllight andiincreases .theusful light output oftube l8 by about 100 per cent.

.The lamp l8'comprisesapair of. legs IBa-and l8b Ialigned with theaxis of .the1h0uSingT28Qand having at their front,end. portionsa spiral connectingtube 18c. asshcwniin' Figure 5. Each-leg l l 8a and [8b.has an electrode 18d lmountef'd on a @conductor [8e extending to the .close'd'ierid .of the leg as shown in Figure'3. Suchconductor [8e extends from itselectrode I 8d throughl the end of the corresponding leg to terminatein a .conducting capllif, Figures 3 and-5, which is external to the tube. The interior of the space defined by thellegs l8a.and [8b, together-with the spiral tube 18a 'is evacuated and a small amount. of mercury placed therein. When'Jhigh alternating. voltage is impressed .across electrodes [8d, aniarc discharge takes place between these electrodes to produce the: intense ultra-violet line characteristic of mercury discharge. The. major portion of the light .producing area :of the .tube l8.comprises the ,convolutions directly behindthe filter 26 So that :efficient productionofiillumina- 'itionsatthe'endofitubelB iszprovided. tIf .azdark' chamber housing-l Otis used, this illumination, of

course, is inthat-chamber. F'ilter 26removes=the visible components of illumination -so that the interior of the chamberlll'is illuminated only with invisible light' and T fluorescence r of the ma- 4 terial in the dark chamber may be observed without interference.

The insulating cap 22 on the rear end of the light housing l8 terminates in a semi-spherical portion 22a which carries on its open face a pair of concentric circular slip rings 34 and 36. These slip rings-are ofcopper, Phosphor bronze, hard spring bronze, or like material, and have conduct- .ing end tabs 34a and 36a, respectively, which extend into the chamber 22?) formed in cap 22. Adjacentshock mount 32, wires 38 are soldered tothe sleeves I81 of lamp I8. The opposite ends of the wires 38 are soldered to the conducting tabs 34a andf36a,.respectively, thus defining a completerconducting path which may be traced from slip ring 34 through tab 34a, one conductor 38 to lamplBto-the other conductor 38 and tab end 3 36a to. theinner slip ring 36. Consequently, when suitable high voltage is available across the slip rings 34 and 36, the lamp l8is energized.

.Tab 36a;is insulatingly held in the-slot 220 of cap ."22 by *the insulating "sleeve 36b shown in 'Figure' l.

The'energizing unit E"has.:at one end aihead portion'38, Figures 2 and 4, which mates withthe head 22a of the lamp housing to-define a com- 'plete conducting .circuitthrough the "slip rings 34 and 36while permitting rock'ing"motion-iof thelamp housing L relative tothe energizing unit E. As shown in Figure 4,-the head portions '38 and 22a 'are'releas'ably securedtogether "by the 'screw"40f.'having at its end a knurled nut -42 which canibe tightened orloosened by 'handto adj ust" thelamp housing L to any desiredposition of tilt in'relation to the'energizing unit-E. The head portion 38, like head 22, is formed of-a unitary piece 'of plastic, 1811011 as Bakelite,= and has a cylindrical portion-38a which is heldin the metal casing 44 by the conicalendwalllda thereof which mates with alike'conical or beveled edge seat "portion cn'the member 38a. The member 38 carries'on its flat face agpair of outer and inner slip rings '46 and 48,*respectively. These mate with and establish a-ccnducting'connection with-the sliprrings-Mand 36, respectively. Each of theslip rings 46;and48 has anelongated conducting tab 46a' and lam respectively. which ex- 'tends through'the opening 882: ofthe head por- 'tion' -38 into the end cavity-38c thereof "where it receives the energizing conductors as hereafter more fully described. The tab -48ais received in the insulating sleeve 50 as shown in'-Figures 2and'4.

The general "construction of the energizing unit E'will'be evident-from Figure 1. Br'ieflyfit consists of an: end cap --52 detachably securedto the end i of the housing-14 opposite the conical portion 44a. This cap receives' the conducting spring 54 which bears against battery 56 "and establishes a circuit connection between the "bottom of the battery and the conducting casing as shown. This connection -'arises-fromthe met that' the spring 5 54 is slightly out or round 'at'its largest portionand resiliently bears against the interior of casing 44. Battery 56 seatsagainst battery 58 which in turn seats-againstthe conducting "casing of the vibrating unit- 68. This yibratingunitis receivedby the transformer unit 62 to which the tabs- 46a and 48a, Figure 2, -'are connected. 'The "vibrator interrupts unidirectional: current "flow from batteries 56 and 'iato cause alternating flux in .the core 1 or the transformer unit 62 to produce the high kvoltage \requisitefor the operation of the lamp l8.

1'The ;construction :of :the vibrator :unit isrshown in detail; in Figure 2 which is an axial cross-sectional view with parts in elevation.- As shown, theunit consists ofa conducting casing I54 of cup-shaped configuration with its bottom 64a resting against ,the electrode 58a of battery 58. Casing 64 is held concentrically within the tube 44 bytheinsulating spacer 68 which is of rubber or like material. At its open end the casing 64 defines an annular interior channel 64b in which the insulating end disk 68 is disposed; A plurality of conducting prongs or pins 68a, 88b, 68c, 68d, 6'8, 68f, and 68g, Figures 2 and 6, are molded in the end disk 88 and extend beyond the confines of the housing as shown. The housing 64 is filled'with a resilient fill material indicated generally at 10. This material may, for-example, be foam rubber.

Centrally disposed within-the material 10 and inspaced relationship with the walls of the housing 64 is a vibrator unit 12, this unit being casing frame 14 made by bending over a fiat steel strip in generally'V-shaped conformation to form a conical neck 74a and 'a'constricted mouth 14b. Insulating spacer sleeves 16a, 16b, and 160 are disposed within the constrictedmouth 14b and support the contact elements 18, 80, and 82 which. as shown, are connected'to the pins 8Ba,-68b, and 680, respectively. 1

A winding 84 is located in the enlarged end portion of the frame-I4 and encircles a centrally disposed magnetic core member 84a, this core member being received by the end 140- of the frame 14. Core member 84a is substantially concentric with tube 44. One end of winding 84 is connected'to the contact element 84b mounted on the core 84a and positioned for engagement with the contact 80a mounted upon the central resilient-"vibrator element 80. This establishes a conducting connection from that end of coil 84 to the frame 14. This frame isconnected by the 'wire 86 to the prong 88c, Figure 6.

"The central or vibrating conductor element 80 isconnected to the pin 68b'a's shown and is made of a suitable magnetic spring material, such as spring steel. Weight 8012 is mounted on its remote end, which is in spaced relation with the tip io'fthe core 84a to impart to the spring 80 the inertiarequired to create the natural frequency of f oscillation required to produce the most effective frequency of current reversal for application tojthe transformer unit 62. I In addition to the contact element 800 which engages the fixed contact84'b, the central spring-like vibrator 80 carries apair of opposed contact elements 800 and, 80dwhich engage the corresponding fixed contact elements 18a and. 82a resiliently carried by'the arms 18 and 82, which elements are respectively connected to the pins GBa'and 68c.

" The "vibrator, in operation, defines a high speed single-pole double-throw switch operating, in one embodiment ofthe present invention, at about The tube prongs orpins 681' and 689, Figure 6, "are not used; A- solder link 69 joins pin68d and therebetween.

casing 60 to establish a conducting connection The-tran'sformerhnitGZ consists of a conductriesf female sockets 94a, 94b, 94c, and 94d which receive the'respective prongs 68a to- 68d.;--Othe r socket elements (not shown) are provided to reacisgs ia *ceive the prongs-68c to 68g. At its opposite end the sleeve 88 receives the portion 38a of head 38 which extends therein up to the-insulating spacer disk 96. A similarspacer disk 98 is locatedin spaced relation with the ends of the sockets 94a to 94d, as shown." The transformer core I00 is located within the space defined by sleeve 88 and spacers 96 and 98 and is supported therein by a resilient fill material I02 which may, for example, be foam rubber. -Windings I04 are mounted on the center leg I00av of the core I00 and are connected as described in further detail hereafter. s I

The vibrator 60 and the transformer unit '62 i are energized at will through the contact making switch defined by resilient conducting leaf I08 which is held to the conducting outer sleeve 44 by' rivet I08 and at its free endbottoms against the detent I I0. When the detent I I0 is depressed. the conducting leaf I06 engages the side of the conducting sleeve 88 to establish a circuit connection through conductor ill to the pin 68d and the winding 84. When this connection is established, the vibrator is actuated and powerjfed through the transformer unit 62 to the'lamp.-

The energizingcircuit for lamp I8 is shown schematically in Figure 7. As shown, the batteries 56 and 58 are connected through'the resilient-switch leaf I06 to the center tapof the primary mm of the transformer windings I04, this connection being made by reason of a conductor extended from the sleeve 88 to'this primary center tap. The ends of primary winding I04aare connected to socket elements 94a and 940 which receive the pins 68a and 680, respectively, to which the contact elements 18a and 82a are connected, respectively.- The sleeve 88 is connected by conductor I I2 to one end of winding 84, this connection being established through the socket 94d and the prong 68:1. The opposite end of the winding 84 is connected to the thereby releases the same to spring to the contact making position. By this action the element vibrates back and forth at a frequency de termined by its natural resonant frequency of vibration.

When the element 80' is in vibration,-contactors 80c and 80d, Figure 2, alternately contact elements 18a and 82a. This causes current now from batteries 56 and 58 to th respective halves of winding I04 thereby creating in the core I00 analternating magnetomotive force and magnetic flux. This induces corresponding alternating voltage in secondary winding I041) to energize the lamp I8. I 1

1 Resistance II4'isprovided across the contacts 84b-and a to minimize sparking and the inci dent' contact pitting. v

Inan actual unit constructed in accordance with the principles of the present invention, the

input current to the winding I04a' was found to average 1.2 amperes and the voltage across the winding found to be 2.9 volts R. M. S. Voltage across the secondary I04bas read by a convexi- .Ltionalindicatingmeten was 2.5ovoltsandthecurrentnow 18.mi11iamper.es. TIFhe volta e v-wave across the-secondary l04 b, however,-was hi hly peakedand; reached momentary values, of 2500 10113831303500 volts. :T-hese peak ,voltages act to :initiate discharge ,in; tube [8 which is; maintained .by the;,lower .voltageduring the remainderof :'e ach ha1f wave.;to give an effective ultraviolet radiation. I V

z-From theabove description itwillbe apparent that; the u1 1it;of;,the. present; invention-;,.acts as an ultra-violet "flashlight nto ;produce ;an efficient ultra-violet illumination from conventional flashlighttype, batteries. The device accomplishes this by the; use ofsmall light weight elements which, by reason of their. disposition,'do not",transier unduevibrationyto thehand of jth e operator or to thel samplebeingtested. ;Moreover, the unit may ;-be completely disassembled by merely re- 1nov ing-v the ;end;cap of the unit, and: withdrawing .thegvariolls portions thereof. If necessary; a replacement 1 vibrator or transformer ,may :be insertedwithout dif iculty. 1

- -'fI he;-dark chamber-housing 1 is ;not necessary to the operation of the lamp unit L-sinceeifective direct observation of fluorescence may be made in subdued light many instances. .The dark chamber l -0;is accordingly the nature of an accessory; that may ormay not i be ;provided as desired.

zWhi1e I 1 have shown and :described a I Specific em odiment jof theipres n i n i n. it w o course :beunderstood IhatI do not wish to-be limited thereto and that many modifications and alternative constructions may be madewithout departing from the true spirit and scope of the invention. :1 therefore intendby the appended -unit comprising a housing snuglyreceived by; the

tube,.a resilient fillmaterial ingthe housing,;and

.-a mechanical contact making vibrator; mechanism disposed in thefill material.

42-. A .self :Ql1tained energizing 5 unit for:a-,mercury qvapor ultra-violet light source vcomprising,

in; cQmbination; ;a lengthy :con duc'tingmousing tube; aninsulating head fixedly disposed in;the

tube and having contact elements adaptedgtoyesceive m rc ry ap r l mp connections; a; trans- .formerunit insulatingly disposedin the tube and abutting the head, the transformer :unit comprising an electrically: conducting sleeve having :a; detachable connectorelement at one end, anda ran o mer z nsulatin ly supported :in the sleeve and having its output connections connected: to

the-said contact-elements and itsrinput ;connec-- tions connected to said connectorelement; switch means accessible from outside the tube and1oper- .able in-the 4 actuated :condition to establish a aircuit from the tube to said sleeve; a vibrator unit adj cent the transformer ,unit, the vibrator I unit com ri n a n t n :housing *i sulatin ly supported-from the tube,- a detachable connector .defining a closedspace in conjunction with-gthe hous n and ece ed by the d ta h ble onn ctor element of the transformer; a;r esilient fill. in;- said :8 space.zian ir vmechanicalrvibrator centrally :disposedin .said fill and, connected to said; last, connecto element; Ba -battery in-,saidtube adjacent the vibrator unit andelectrically connectedltothe hous ngganda cap forotha endof the-tube having resilient lelements urging the transformer. ,vibrator, and ,battery :together and-,establishingea connection fromthebattervto thetube.

1-3. In;a selt-contained-unittoenergizeamercury vaporm1travio1et-light= or the. likefi-thelimprovement .comprising: :a 'rlengthy conducting ;.tnbe; az transformer unit.-within=;thertube,; theunit comprisin saeconducting psleeve; insulatingly'. mounted ,withinlthetubcr a transformer :within. the sleeve. .and, longitudinally.separable .connectorsterminals atoneendy-pa vibrator-unit within the tubeazand adjacent said end of the transformenunitnthe vibrator unit/ comprising ;a cup-shapedconducting. housing, a vibrator ;s.upported .i-n the...,housingmand connector: ;terminals ,at .the .open' end receivedrby the terminals .of the. transformer. unit; and switch elements ,selectively operable ,.to-. establish. a circuit cconnection between ,the ...tube and the sleeveofthe. transiormerimitnthe transformer unitrand thelvibratorrunitoha-ving. cooperating rcircuitr connectionsnto, energize the .transformer and" vibrator when .,D. -,C. ,voltage .is "impressed between the housing of the-vibrator and :the tube and the switch elementsraretclosed.

:4. Ina ,self;contained unit .to energize .a .mercury vapor ultravioletslightc or: the like, .-.the .improvement comprising: 4.3, Jengthy conducting tube; ta transformer unit within the tube, ,the unit-comprising-g-a conductingsleeveinsulatingly I mounted within the tube,v a. transformer ;,witl 1in the sleeve, and [longitudinally \separable -con nector; terminalsat one end .,a=vibrat0r,unit with- :illrthfi tube .and adjacent, said end. of .the transformerqunit the :vibratonhnit comprising acupshaped. conductinghousing-a vibratorgsupported in the housing, :and connector rterminals. at .the :openendzreceived by the {terminals of- ,the ,transformer: unit; andswitch elements selectively, operabletdestablishra circuit connection betweenthe tube-and. the, sleeve of .the transformer unit; the transformer-innit, having circuit connections from he-transformerand the-tube to .the connector terminals, and-the vibratorlunit having, cooperating-rcirc,uit connections from ,thevibrator to ,the =vibrator ,unit connector terminals and ..to ,the housing of t-he .vibra'toreto energizeihe .trans- ,-former. and vibrator -when-,D.-C.,ro1tage is im- ;pressedlbetween.the ,housing .of the vibrator. and the tubeand the switch elements are ..closed. V A se1 f..-,contained,.unitQto,energizes.mercury vapor .ultravioletlig-ht or .thelikeiromflashli'g'ht batteries comprisingin combination; a lengthy conducting, tube ,atransformer. Amitaat: one end of the tube, the unithaving, a conducting .isleeve .-insulatingly receivedeinethe :tube, antransformer :carried by-theisleeve,sand glongitudinally separable connector terminals at v-on,e,end ofthesleeve and connected -,to :the ,transformer andto the sleevera vibrator ,unitreceived in the (tube adja- .cent .-the,tran sformer ,unit, @the vibrator ,unit having a cup-shaped housing insulatingly receivedin the tube,,-a vibrator in the housing. .connector terminalslmatingwith theiterminalslof the transformer unit, and circuit connections from :the vibrator to-the terminals and the. housing; switch elements operable :to establish I a circuit connection vfromthe tube to the sleeve, the-tube randthevibratorhousi-ng being adapted to receive flashlight cells and .aclosure: for the. ienduof the tube; operable to establish contact betweennthe end cell and the tube and to compress the vibrator housing and, adjacent cell into contact-making position.

6. A self-contained unit to energize a mercury vapor ultraviolet light or the like from flashlight batteries comprising in combination; a lengthy conducting tube; a transformer unit at one end of the tube, the unit having a conducting sleeve insulatingly received in the tube, a transformer carried by the sleeve, and longitudinally separable connector terminals at one end of the sleeve and connected to the transformer and to the sleeve; a vibrator unit received in the tube adjacent the transformer unit, the vibrator unit having a cup-shaped housing insulatingly received in the tube. a vibrator in the housing and fioatingly supported thereby, connector terminals mating with the terminals of the transformer unit. and circuit connections from the vibrator to the terminals and the housing; switch elements operable to establish a circuit connection from the tube to the sleeve, the tube and the vibrator housing being adapted to receive flashlight cells; and a closure for the end of the tube operable to establish contact between the end cell and the tube and to compress the vibrator housing and adjacent cell into contact-making position. 7

CHARLES WEEKS.

REFERENCES CITED Thefollowingv references are of record in the file of this patent:

UNITED STATES PATENTS 

